Fuel supply mechanism



April 21,19 2. c. F. STEHLE mL 2 280,317

FUEL SUPPLY MECHANISM Filed Aug. 7, 1939 2 Sheet s-Sheet l 51 B Ewen/11v0pm;

ATTORNEY v April 21,1942 7' c ESTEHLE 2,286,317

FUEL SUPLy MEGHANiSM Fi-led Aug. 7, 1959 .2 Shets-She'et 2 lNvENTdRc'zmz. 175mm w BY 11mm 620,210:

- ATTORNEY Patented Apr. 21, 1942 FUEL SUPPLY MECHANISM Carl "F.Stchle,Caldwell, and Herman Glodde, Paterson, N. J.

' Application August], 1939, Serial No. 238,823

10 Claims.

Our invention relates to fuel, supply mechanism for delivering fuel tothe cylinders of internal combustion engines, and in particular to thetypewhere the fuel is dispensed to the cylinder independently of themajor portion of the air required to support complete combustion of thefuel. l

It is known that heretofore fuel supply systems of the so-called solidinjection type have been employed to deliver measured quantities of fueloil to an internal combustion engine independently of the air. Suchsystems have included a cylinder into which thefuel is drawn duringoutward movement of a piston therein, and from which the fuel isdischarged during inward movement of the piston, the length of thepiston stroke normally being'variableto regulate the charge of fueldrawn into theinjection cylinder.

Such devices have operated satisfactorily where the fuel dispensed hashad lubricating qualities sufficient to lubricate properly the pistonand cylinder walls of the injectorwith which it comes into directcontact, or which at least will not render ineffective the lubricatingvalue of a lubricant independently applied to the piston and forexample, the air to support combustion is all, or nearly all, deliveredto the engine intermixed with the gasoline. Such delivery isaccomplished entirely by pressure differential instead of by positivemetering and delivery mechanism. It is therefore difficult to insurethat precisely the desired quantity of fuel is delivered at all speeds,and the change in fuel supply for variation in engine speed willprobably not, .over the whole range, bear a constant or consistentrelationship. Moreover the fuel is imperfectly atomized by carburetionso that the efficiency obtained from its combustion is low.

In order to obtain the advantages of positive,

solid injection fordelivery of a fuel devoid of substantial lubricatingqualities, such as gasoline, we have devised our fuel injectingmechanism hereafter described. Primarilyv such mechanism consists of aunit which contains a fuel metering der.

chamber adjacent to and in communication with an injection cylinder.Fuel is supplied to such chamber and forced therefrom' into an enginecylinder, without entering the injection cylinder, by air which iscompressed in the injection cylin- Air alone is taken into the injectioncylinder and forced therefrom so that the piston and cylinder walls maybe lubricated in any conventional manner suitable for lubricating theequivalent parts of an air compressor, without danger of the lubricantbeing adultered or its lubricating qualities counteracted by the fuel.Fuel is delivered to the metering chamber and air to the injectorcylinder during the pistons outward movement, and at the end of itsinward movement the compressed air drives the charge of fuel from thefuel chamber into the engine. The size of the fuel chamber or the amountof fuel delivered thereto may be varied to change the amount of fuelcharge to be dispensed. Admission of the fuel to the metering chambermay be governed either automatically by pressure sensitive mechanism orby mechanically actuated valves.

The principal object of our invention therefore is to provide aninjector type, fuel supply mechanism capable of delivering fuel whichhas no lubricating qualities to an internal combustion engine. v

More specifically it is an object to provide such an injector of thepiston type in which the fuel delivered does not come into contact withthe injector piston or cylinder, but instead the fuel is forced into thecylinder by air compressed in the injector cylinder by its piston.

In an injector having such an operation it is a further object toprovide a lubrication system for the injector piston and cylinderentirely independent of the fuel and which will not be affected by thefuel.

Another object is to provide an injector of the type stated in which thefuel is dispensed from an antechamber of the injector cylinder and whichmay have either a pressure controlled or a mechanically operated valvearrangement for supplying fuel to such antechamber.

It is a further object to provide means by which, with either type ofvalve arrangement, the charge of fuel delivered to the injector fuelchamber may be regulated accurately and may be controlled readily tovary the charge according to the power which it is desired that theengine deliver and the speed at which it is to operate.

By employment of mechanism which will accomplish these objects we obtainmore accurate feed of fuel to the engine and such fuel is morethoroughly atomized to afford more complete combustion and betterefficiency.

It is also an object to provide such injector mechanism which can beapplied equally well to engines operating on a four stroke cycle as tothose of the two stroke cycle type. In the latter type the fuel need notbe forced into the cylinder until after the burned gases are scavengedfrom the engine cylinder by air alone.

Another object is to provide such an injector unit which will be small,compact, and of light weight, yet which will be substantiallyconstructed.

Other objects of our invention which are inherent in particular featuresof the construction which we employ will be understood from thefollowing description of our device.

Preferred embodiments of our device are shown in the drawings toillustrate novel features incorporated in our invention as defined inthe appended claims, the construction of these devices being describedhereafter.

Fig. 1 is a vertical section of our injectoi mechanism taken along line.of Fig. 2.

Fig. 2 is a front elevation view of the injector mechanism.

Fig. 3 is a partial vertical section taken along line 3-3 of Figs. 1 and4.

Fig. 4 is a plan view of the injector mechanism showing parts thereofremoved.

Fig. 5 is a partial vertical section similar to Fig. 3 illustrating amodification.

Fig. 6 is an enlarged fragmentary section taken along line 6-6 of Fig. 3showing valve mechanism.

Fig. 7 is a Vertical section similar to Fig. 1 showing a furthermodified unit.

Fig. 8 is a fragmentary section taken along line 8-8 of Fig. 7.

Fig. 9 is a side elevation view of the injector shown in Fig. '7.

Fig. 10 is a vertical section showing a modified cylinder and pistonactuating mechanism.

In the illustrations and description our injector mechanism will bediscussed in its application to a single engine cylinder. It will beunderstood, however, that such mechanism is also adapted for supplyingfuel to multi-cylinder engines, in which case it will be mostadvantageous to provide a separate unit for each cylinder andcoordinating mechanism by which the operation of the several units maybe properly adjusted for their respective cylinders, and by which theircontrol may be synchronized as desired to vary the operating speed andpower of the engine. The injector mechanism is equally well adapted tofunction in conjunction with engines operating on the two stroke cycleor the four stroke cycle. In multi-cylinder engines, especially of theformer type, it may be advantageous to feed from a single injector unittwo or more cylinders in all of which the power strokes substantiallycoincide.

In the drawings the connection of the injector to an engine has not beenshown, nor the injection nozzle, for this may be any one of varioustypes depending largely on the type of fuel employed, the design of theengine, in particular of the piston and cylinder head, and the locationof the injection nozzle in the cylinder head. Aproper nozzle type may beselected by one skilled in the art with regard to these considerations.As has been discussed previously,

our injector is intended principally for supplying to an internalcombustion engine cylinder a fuel which does not have sufficientlubricating properties to lubricate the piston and cylinder of aninjection pump with which it is in direct contact, a common example ofsuch a fuel being gasoline.

One form of our injector mechanism which has operated successfully isshown in Figs. 1, 2, 3, 4 and 6. The fuel is forced into the enginecylinder along with a small amount of compressed air, very much lessthan that required for complete combustion of the fuel. Moreover theamount of air discharged with each charge of fuel will always besubstantially the same for a given installation whatever the operatingspeed of the engine or the size of a fuel charge.

The injector unit consists primarily of a cyl inder I and a head block 2mounted on top thereof. The fuel is admitted to the head block undervery small pressure, such as that of a gravity feed or continuouspressure pump or tank, through the inlet port 20, and is discharged inintermittent, measured charges to its cylinder through the outlet 2|, asindicated by the arrows in Figs. 2 and 4. An overflow connection 2| mayalso be provided for trapped fuel vapor, which will communicate with thefuel suply. As will be discussed hereafter it is not essential to havesuch an overflow connection in certain instances. The cylinder I has anair supply port I!) (Fig. 3) controlled by a spring biased valve so thatit will normally be closed, but it will be forced open against thespring action by atmospheric pressure on the suction stroke of thepiston l2. A passage 23 places the cylinder in direct communication withits fuel antechamber 22 in the head block 2. This passage is normallyclosed by a valve 24 held to its seat by a fairly stiff spring receivedin the fuel chamber. A further, light check valve 25 is dis posed in theoutlet 2| to prevent any fuel being forced back into the injector unitfrom the engine cylinder, and further to prevent fuel which is beingsupplied to the chamber 22 through port 20 from flowing out through theoutlet to the engine under the small pressure at which the fuel issupplied, instead of being discharged only during the injection period.

Within the head block 2 are formed a valvereceiving aperture 26 andpreferably a second valve aperture 21, the former being in communicationwith the inlet port 20 and the latter being drained by the overflow duct2| Each of these apertures has one end in direct communication With thefuel chamber 22 and is provided with a valve seat at such end. Aperture25 preferably has a conical valve seat, as shown enlarged in Fig. 6,while that of aperture 21 may conveniently be concave to be sealed by aball-shaped valve. The opposite end of each aperture is threaded toreceive a plug 3| which may serve as a valve stem guide. Inlet 20 opensinto the conical seat of aperture 26, being disposed at an acute angleto the apertures axis as shown in Fig. 6 so that it is directedtherealong toward the fuel chamber 22. On the side of the conical seatremote from the fuel chamber and spaced therefrom an annular recess 28opening outward from aperture 26 may be provided to serve as a leakagetrap to receive fuel which may leak past the valve in this aperture. Aduct connecting this recess with aperture 21 serves to empty fueltherefrom through overflow port 2| back to the fuel supp y.

In the apertures 26 and 21 are received, re-

each time the main crank shaft rotates.

spring 33, encircling the valve stem, is interposed between the head 32of valve 3 and the plug 3| to urge the valve normally to closedposition. Valve 30 preferably has a ball shaped head 34 complemental tothe valve. seat in aperture 21, and substantially smaller than suchaperture to afford an opening of considerable size from chamber 22 toaperture 21 upon slight unseating movement of the valve. This valvelikewise is normally pressed to its seat by a similar spring 33interposed between its head 34 and its plug SI and encircling its stem.I

In this form of injector unit positive valve operating mechanismisemployed, driven in synchronism with movement of the pistonin cylinderI from crank shaft I3. An exampleof a suitable type of operatingmechanism is illustrated, including an eccentric cam I {mounted on shaftI3 to raise lifter rod I as it rotates.

This rod, by its upward movement, tilts a bell crank lever 35 by forcingupward its'horizontal arm. The resultant swinging of its upright endeffects simultaneous reciprocation of the valves 3 and to which it isconnected through the medium of a crosshead 36 joining the valve stemsand a rod 31 secured to the center of the crosshead and pivoted to theupright end of the bellcrank arm.

In order to synchronize the movement of the valves 3 and 3|] with theoperation of the engine pistons, it is preferred that crank shaft I3 bedriven mechanically by the engine in some suitable manner (not shown).If the engine operates on a four stroke cycle the speed of crank shaftI3will be one-half that of the main engine crank shaft, whereas if theengine be of the two stroke cycle type the speed of'the crank shaft I3will be the same as that of the main engine crank shaft, so that acharge of fuel will be delivered to the antechamber 22 and such chargewill be forced therefrom into an engine cylinder piston I2, also beingdriven by the crank shaft I3, will, of course, move in synchronism withthe push rod I5.

In the type of injector unit illustrated in Figs. 1 to 4, inclusive, thesize of chamber 22 is not altered and hence in order to vary the speedor the amount of power delivered by the engine it I is necessarythat theamount ,of fuel admitted to chamber-22 berregulated accordingly. Thismay be accomplished by changing the length of time during which thevalve 3 isunseated from the seat in aperture 26. The fuel will flowrelatively slowly through the inlet passage 20 because of its small sizeas shown in Fig. 6. The duration of valve opening may conveniently beregulated by providing a wedge 38 interposed between the lifter rod I5and the horizontal end of the bellcrank which may be moved endwise by athrottlehandle 39, as shown in Fig. 2, between the solid and broken linepositions. The push rod I5 may be held in contact with this wedge by theprovision of alight spring encircling it and bearing against a shoulderthereon as shown in Figs. 1 and 2. Obviously suchspring will not.

The

two springs 33 encircling the stems of valves 3 and 30 so that it wouldunseat such valves without engagement of cam I4 with lifter rod I5. Inorder to change the effective length of push rod I5 by lengthwisemovement of wedge 38, the

cam I4 and the lower end of the push rod will 1 normally be spaced apartas shown in Figs. 1 and 2. As the-piston I2 is moved downward the highportion of th cam will turn into contact with the lifter rod andraise itto open valves 3 and 30. v If .wedge 38 is well over to the left, asshown in Fig. 2, the duration of the cam and lifter rod engagement-willbe short, whereas if (ill the wedge is moved over to the right byswinging the throttle handle 39 the lifter rod will be forced downwardso that it will be in contact with the cam I4 over a longer timeinterval, and hence valves 3 and 30 will remain open for a longer periodto enable a larger charge of fuel to enter chamber 22. Obviously theshape of the cam I4 and the angular relationship between the highportion thereof and thethrow of the crank shaft to which the connectingrOd of piston I2 is attached may be varied to alter the time at whichfuel is supplied to the chamber 22 and the length of such deliveryperiod. Ordinarily these factors arenot very critical. I

After the charge of fuel has been delivered to theantechamber 22, pistonI2 will be moved the remainder of its travel upward on the compressionstroke. passage 23 affording communication between cylinder I andchamber 22, must be opened at or near the end of the pistons compressionstroke. Preferably this action is accomplished positively by theprovision of mechanism actuated by the piston asit moves upward, such asby a tip I6 provided thereon which will move up through passage 23 toengage the valve ball 24 and raise it from its seat as shown in Fig. 1.If desired, however, the opening of the valve may be accomplished simplyby the pressure differential between the cylinder I and chamber 22, sothat, as shown in Fig. '7, when the piston nears the end of itscompression stroke the pressure of the air will be sufiicient to forceopen valve 24' against the pressure of its spring to allow the air topass through duct 23 into the fuel chamber and to force the fueltherefrom out through the outlet 2| to the engine past check valve 25.

While the pressure operated type of valve controlling admission ofcompressed air from the cylinder I to chamber 22 has been'illustratedonly in Fig. 7, it will be understood that this structure may beincorporated in the device of Figs. 1 to 45, inclusive, instead of thatshown therein if desired.

In operationrcrank shaft I3 is driven at the appropriate speed, aspreviously discussed. By its rotation piston I2 is drawn downward whichcreates a partial vacuum in the upper portion of cylinder I, valve 24being closed, so that atmospheric pressure forces downward valve I I toopen port Iii. Air then flows through the apertures arranged about thevalve stemto fill the cylinder during the suction stroke. Duringdownward movement of the piston the high portion of cam M is alsorotated by crank shaft I3 into engagement with the lower end of lifterrod I5. Raising of this rod rocks -bellcrank 35 toward the brokenpositionflof Fig. l to unseat valves 3 and 30. At this time valves 24and 25 will both be closed and a stream of fuel will be admitted to thechamber 22 through ductfZil shown in Fig. 6. This duct, as illustrated,being disposed at an Valve 24, which normally closes acute angle to theaperture 26 will direct a stream of fuel therealong into the fuelchamber. Since valve 30 is ball-shaped slight movement thereof will opena large opening to afford easy escape of air and fuel vapor trapped inthe antechamber 22. Depending on the position of wedge 38 (Fig. 2) ascontrolled by throttle lever 39, the duration of valve opening may beregulated by causing push rod I to be forced downward a greater orlesser distance against its spring so that its lower end will becontacted for a greater or lesser interval by the high portion of camI4. Since duct 2|] is relatively small the fuel charge entering chamber22 will be varied according to the length of time valve 3 is held in theunseated position. It will be understood that with the wedge 38 in theleft hand position the valves will be open for a comparatively shortperiod and the fuel chamber will have only a small amount of fueldelivered thereto. 'As the throttle lever 39 is swung to the left andthe wedge is thereby moved to the right a progressively larger charge offuel is delivered to chamber 22. If this chamber is sufficiently largeso that even when the wedge 38 is moved clear to the right the fuelcharge is insufficient to fill completely chamber 22 valve 30 may beomitted.- As stated, the purpose of this valve is to allow the air andfuel vapor to escape from the chamber, but, since the fuel flows throughduct 20 into the chamber under a small amount of pressure, such air andfuel vapor as is present in the chamber may be compressed into a smallportion of the chamber by the inflowing liquid fuel even if means forits escape is not provided.

As crank shaft I3 continues to rotate piston I2 will be moved upward onthe compression stroke whereupon valve II will be forced closed,preventing further admission of air to the cylinder. During this upwardstroke the high portion of cam I4 will release push rod I5 so thatsprings 33 may close valves 3 and 30, the fuel charge in the'desiredquantity then being in chamber 22. As the piston nears the top of itsstroke its tip I6 will pass upward through the intercommunicatingpassage 23 to contact valve 24 and raise it from its seat. As previouslydescribed, this valve may, instead of being opened mechanically, beforced open by the pressure of the air compressed in cylinder I duringthis compression stroke. As soon as valve 24 opens the compressed airrushes from cylinder I into chamber 22 and expels the fuel therefromthrough the outlet 2| past check valve 25. As the piston starts to movedownward again valve 25 will, of .course, close under its spring actionwhile valve 24 will remain open until after the piston has retreatedsufiiciently to withdraw pin IE from contact therewith. During thismovement the suction created by the piston will tend to remove fromchamber 22 some of the air and fuel vapor remaining therein.

The cylindricalportion 32 of valve 3, as shown in Fig. 6, is closelyembraced by the wall of aperture 25. Since the fuel admitted throughduct 20 is under low pressure very little will be able to pass betweenthe valve body and the aperture wall. This slide fit may not be leakproof, however, and what fuel does pass the valve head will be collectedin the annular space 28 from which it will be removed through the ductshown in Fig. 1 to aperture 21 whence it will flow out through theoverflow port 2| which communicates with aperture 2! to remove also airand fuel vapor therefrom.

Fig. 5 illustrates an alternative way in which air may be supplied tothe cylinder I which is especially advantageous Where a higher injectionpressure is desired. The air supply arrangement resembles structurecommonly employed in a two stroke cycle engine for delivering thecombustible mixture to the power cylinder. It includes an air intake forthe crankcase controlled by a check valve I! and a bypass passage I8affording communication between the crankcase and the upper portion ofthe cylinder. We prefer that an additional air inlet, controlled bycheck valve I I be provided in the upper end of the cylinder. As thepiston moves downward, therefore, after an injection stroke air and fuelvapor are removed from the antechamber until valve 24 closes. Thereafterair is drawn into the upper portion of the cylinder past check valve II'until the piston has descended sufiiciently to uncover the upper end ofpassage I8. Meanwhile air previously drawn into the lower portion of thecylinder and crankcase past check valve I! on the compression stroke ofthe piston has been compressed in the crankcase as the piston moveddownward. When the upper end of passage I8 is uncovered, therefore, thisair under pressure will rush upward through the passage to supercharge,in effect, the upper portion of the cylinder. The check valve I I willthereby be forced closed and the air in the upper portion of thecylinder will be under pressure greater than at mospheric at thebeginning of the pistons compression stroke. A higher injection airpressure may thus be obtained, or if no higher pressure is needed thelength of piston stroke may be reduced to make the mechanism morecompact without decreasing the effectiveness of its operation.

Instead of actuating the valves for supplying a charge of fuel to thechamber 22 by mechanical linkage, a pressure operated construction maybe employed, such, for example, as illustrated in Figs. 7, 8 and 9. Herealso a cylinder I is provided which is in communication with a fuelantechamber 22' through a passage 23' controlled by a valve 24. The headblock 2 has been shown as cast integrally with the cylinder although itmay be merely secured thereto as in the form illustrated in Figs. 1 to4, inclusive, if desired. Here also a fuel outlet 2|, controlled by acheck valve 25, is provided. Also we have illustrated an air inlet forthe upper part of cylinder I controlled by a check valve II which may beused in place of the type of air inlet valve II controlling inlet ID ofFig. 3.

Instead of providing mechanically operated valves 3 and 30, a body 4 isreceived in the side of block 2 and preferably acts as one wall ofchamber 22'. In this body are formed longitudinal and parallel passages4| and 42, the former being the fuel supply passage fed by inlet 40, andthe latter being an overflow passage emptied by a connection 43 whichwill drain into the fuel supply. In this form also the fuel will beunder a slight pressure such as afforded by gravity feed, for example.Communication of these passages with antechamber 22 is controlled by avalve rod 44 which is held by a spring 45 to press a head or disccarried by rod 44 against the end of body 4 in a position to cover theends of passages M and 42. During downward movement of piston I2, valve24 will be closed and the slight pressure of the fuel in passage 4I willforce open the valve head against the action of spring 45 suflicientlyso that fuel may flow into antechamber 22'. As this antechambergradually fills with fuel the air and fuel vapor will be bled outthrough overflow passage 42. Passage 4! is of a sufficient size so thatchamber 22 willbe filled. completely with fuel prior to opening of valve24. When it has become filled the pressure of the fuel on the valve discwill be equal on both sides thereof so that the spring 45, drawing stem44 outward, will causethe head to cover once more the ends of passages4i and 2 as shown by the broken circle in Fig. 8. When air underpressureenters chamber 22, upon valve 24 being unseated either by airpressure alone or by mechanical means, such as described heretofore, thefuel will be propelled from chamber 22 past check Valve 25 and outthrough the outlet 2|. During this operation no additional fuel will beadmitted to the antechamber for the air pressure therein will supplementthe action of spring 45 to hold the valve disc seated.

In this type of structure it will be seen that the chamber 22 will befilled completely with fuel prior to each injection operation. In orderto vary the fuel charge delivered to the engine,

therefore, we may vary the size of chamber 22'.

This may be accomplished byproviding a plug 46 forming"a large part ofone wall of chamber 22 and fitting closely within a bore in head block2. On the outer end of this plug is formed a thread 41 having averysteep pitch and cooperating with an internal thread in block 2.

Slight rotation of the plug by means of a control handle 48 willtherefore cause a relatively large endwise movement of the plug.Rotation'of. the handle 48 in a clockwisedirection as seen in Fig. 9

will move plug 46 inward to decrease the size of chamber 22, whereasrotation in a counterclockwise direction will withdrawn the plug toincrease the size of the fuel chamber, enabling a larger fuel charge tobe received therein. It is believed that the operation of thismodification will now be understood without further description, sincewith theexception of the manner in which fuel is supplied to theantechamber the operation is similar to that of the construction shownin Figs. 1 to 4,inclusive.

As stated, the application of our injector to a single engine cylinderhas been described. For use upon a multi-cylinder engine a unit willordinarily be provided for each cylinder and these must be controllablein synchronism -to afford proper engine acceleration and deceleration.This operation may readily be accomplished in the modification of Figs.7 to 9, inclusive, by connecting together the levers 48" of all injectorunits by a push rod 49 provided with an operating handle.

which may be rotated by a single control handle 39; The butterfly valveor other air control will, of course, not alter the amount of airsupplied by the injector which is a small proportion of the whole amountof air required to support combustion of the fuel.

-Moreover, as previously stated, our injector It is also desirable tosynchronize-- changes in the amount of fuel charge with a corunits maybe used with either a two stroke cycle" engine or a four stroke cycleengine. In the former type the fuel may be injected at any time afterthe exhaust and air supply ports have closed so thatscaveng'ing of theexhaust or burned gases from the engine cylinder will be accomplishedentirely by air rather than by a combustible mixture as is usually thecase. A considerable increase in fuel economy is thereby accomplished.

largely immaterial during which portion of the suction stroke the fuelis injected. Better operating efficiency even inthis type of engine isob-v 'As pointed out above, a more instantaneous injection operation maybe accomplished by increasing the speed of piston movement on thecompression stroke as well as by varying the other factors mentioned.Such increased speed may be eifected by the mechanism shown in Fig. 10without changing the engine speed. It is assumed that the crank shaft [3is rotating in a clockwise direction as indicated by the arrow. On thisis mounted a cam 5 which engages with a lobe 5|.

carried by a yoke 50 which is attached to the end of a lineallyreciprocatingrod 52 guided in an. aperture 53 in thecrankcase andconnected to piston l2. E ncircling this rod and interposed be-.

tween the crankcase and the piston is a very stiff compression spring54. As the shaft 13 rotates.

in the direction indicated, the pressure of cam Bagainst lobe 5l.willdraw piston 42 downward and simultaneously compress its spring betweenthe crankcase and piston. As the cam moves beyond the position shown inFig. 10, lobe 5| will rideoff the highpoint of cam 5 and spring 54willinstantly force. piston I2 upward with a very] quick movement. Itwill be obvious that mechae nism of this type will operate best with a.piston having a relatively short stroke. The proportions of cam5 andlobe 5|, may be altered to vary the length of piston stroke and theabruptness with which the cam 5 will releaselobe 5| for upward movementof the connecting rod 52 and piston I2.

This structure may, of course, be employed equally well with either themechanism of Figs. 1

to 4,,inclusive, or the modification shown in Figs.

7 to 9, inclusive.

Asour invention, we claim:

1..An injector for supplying fuel to an in ternal combustion-engine,comprising a cylinder, an all ,inlet porttherefor, a piston reciprocabletherein, a head block on said cylinder having therein a fuel antechamberadapted to communicate with saidcylinder, and a fuel supply aperture anda relief aperture branching from such antechamber, a valve seat in eachsuch aperture adjacent to the antechamber, a valve received in eachaperture adapted to. close the valve seat ofits' respective aperture,and means operating to reciprocate saidpiston and in synchronismtherewithto open simultaneously and to close simultaneously said valves,for scavenging of air. from said antechamber through the relief apertureand for delivering a fuel charge through the" supply aperture into theantechamber prior to admission of air under pressure from said cylin- Ina four stroke cycle engine itis der to the antechamberto propel the fuelcharge therefrom to the engine,

2. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a head block on said cylinder having therein a fuel antechamberadapted to communicate with said cylinder, and a fuel supply apertureand a relief aperture branching from such antechamber, a valve seat ineach such aperture adjacent to the antechamber, a valve received in eachaperture of a shape complemental to its respective valve seat to closethe same, a crosshead connecting said valves, a bellcrank connected tosaid crosshead, a push rod reciprocable to rock said bellorank, cammeans. operable to reciprocate said push rod, a shaft rotatable toactuate said cam and to effect reciprocation of said piston insynchronism, for delivery of a fuel charge through the supply apertureintothe antechamber. and for scavenging of air from said antechamberwhen the valves are moved to open position prior to admission of airunder pressure from said cylinder tothe antechamber to propel the fuelcharge therefrom to theengine, and means to vary the effective stroke ofsaid push rod toalter the duration of valve opening with relation to thespeed of crank shaft rotation.

3. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a head block on said cylinder having therein a fuel antechamberadapted to communicate with said cylinder, and a fuel supply apertureand a relief aperture. branching from such antechamher, and pressurecontrolled means adapted to cut off communication between theantechamber and the two apertures after archarge of fuel has beendelivered to the antechamber and prior to admission of air underpressure from said cylinder to the antechamber to propel the fuel chargetherefrom to the engine,

4. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a head'block on said cylinder having therein a fuel antechamberadapted to communicate with said cylinder and a fuel supply aperturebranching therefrom, means operable to vary the effective size of suchantechamber, and pressure controlled means adapted to out offcommunication between the antechamber and" the fuel supply apertureafter such antechamber has been substantially filled with fuel from'suchsupply aperture and prior to admission of air'under pressure from saidcylinder to the-antechamber to propel the fuel charge therefrom to theengine.

5. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a body having therein a fuel antechamber adapted to communicatewith said cylinder and with such engine, and a fuel supply aperture anda relief aperture branching from such antechamber, the relief aperturebeing disposed above and parallel to the fuel supply aperture, and valvemeans simultaneously controlling communication between said antechamberand both of said apertures, opening said relief aperture to convey gasfrom the antechamber and simultaneously opening said fuel supplyaperture to deliver a charge of fuel to the antechamber, maintainingboth apertures open during supply of such fuel charge to the antechamberand thereafter closing simultaneously both of said apertures prior toadmission of air under pressure from said cylinder to the antechamber topropel the fuel charge therefrom to the engine.

6. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a head block on said cylinder having therein a fuel antechamberadapted to communicate with said cylinder, and a fuel supply aperturebranching from such antechamber, a valve seat in such aperture adjacentto the antechamber, a valve received in such aperture of a shapecomplemental to its valve seat to close the same, a bellcrank connectedto said valve, a push rod reciprocable to rock said bellcrank, cam meansoperable to reciprocate said push rod, a shaft rotatable to actuate saidcam and to effect reciprocation of said piston in synchronism, fordelivery of a fuel charge through the supply aperture into theantechamber when said valve is moved to open position prior to admissionof air under pressure from said cylinder to the antechamber to propelthe fuel charge therefrom to the engine, and means to vary the effectivestroke of said push rod to alter the duration of valve opening withrelation to the speed of crank shaft rotation.

7. An injector for supplying fuel to'an internal combustion engine,comprising a cylinder, an air inlet port therefor communicating directlywith the atmosphere and independent of such engine, a pistonreciprocable in the cylinder, a body having therein a stationary fuelantechamber adapted for communication with said cylinder, an air valvebetween said cylinder and fuel antechamber, means positively holdingsaid air valve closed during the major portion of the inward,compression movement of said piston, fuel supply means communic'atingdirectly with saidstationary antechamber, including a fuel valveseparate from and movable independently of said air valve for deliveringfuel to said antechamber while said air valve is closed, an outlet fordischarge of fuel from said antechamber to the engine by air compressedin said cylinder by its piston flowing past said air valve into andthrough such antechamber, and fuel valve operating means operable toopen said fuel valve while said air valve is closed and to close saidfuel valve prior to opening of said air valve for admission to saidantechamber of air compressed in said cylinder.

, 8. An injector for supplying fuel to an internal combustion engine,comprising a cylinder, an air inlet port therefor, a piston reciprocabletherein, a head block mounted on top of said cylinder having therein astationary fuel antechamber above said cylinder and adapted tocommunicate therewith, an air valve in the head of said cylindercontrolling communication between the cylinder and antechamber, a springholding said air valve closed during the major portion of thecompression movement of said piston, said antechamber having an apertureextending generally radially outward'from one side thereof, a fuel valveseat in such aperture coaxial therewith and adjacent to saidantechamber, a fuel valve received in and reciprocable lengthwise ofsuch aperture, and adapted to seat upon said fuel valve seat by movementlengthwise of said aperture, and means operating to reciprocate saidpiston and also to reciprocate said fuel valve toward and away from saidseat in synchronism, to open said fuel valve for delivery of a fuelcharge past said valve'directly to said antechamber through the headblock aperture while said air valve is held closed by said spring,and'to seat said fuel valve before opening of said air valve foradmission of air under pressure from said cylinder to the antechamber topropel the fuel charge therefrom to the engine.

9. In an injector for supplying fuel to an internal combustion enginecylinder having a fuel antechamber adjacent thereto, such antechamherhaving an aperture extending outward therefrom, a fuel valve seat insuch aperture adjacent to the antechamber, and tapered toward the antechamber, a fuel valve received in such aperture and having a headslidably fitting the walls of such aperture and thus guided forlengthwise reciprocation, said head being tapered toward the antechambercomplemental to said valve seat and adapted for sealing contacttherewith over a considerable distance lengthwise thereof, a fuel sup--ply duct terminating in an opening in the tapered fuel valve seat in thezone of valve head contact therewith, said duct at such opening beingin-' clined toward the antechamber with respect to the radiallyextending aperture, the fuel valve, when in seated position, coveringsuch opening, and means for sliding said valve head away from said seatlengthwise of such aperture to afford an uninterrupted passage from saidfuel supply duct between the valve head and valve seat to theantechamber.

10. In an injector for supplying fuel from an antechamber to an internalcombustion engine,

valve mechanism, including a valve body having therein a cylindricalvalve aperture disposed generally radially of the antechamber and open-,

ing into it, a conical valve seat in the antechamchamber opening of suchaperture, a valve received in said aperture including a cylindrical headclosely fitting therein and guided for lengthwise reciprocation bysliding engagement with the walls of said aperture, the inner end ofsaid valve head being inwardly tapered conically complemental to saidvalve seat and contiguin seated position, covering such opening, and

said valve further including a valve stem within said valve aperturebehind and smaller than said valve head to define a trap cavityencircling said stem and within such aperture for fuel leaking past saidvalve head, and a passage communicating with said trap cavity forremoving fuel therefrom.

CARL F. STEELE. HERMAN GL'ODDE'.

